Early development

In order to perform repetitive assays, simple systems with mechanical feeding/washing of the flow cell were conceived in the early nineteen fifties, and a wide variety of flow spectrophotometers, turbidimeters and nephelometers were already commercially available in 1955 [6]. This approach is still exploited, mainly in connection with process analyses. 

Another relevant feature common in the 1950 s was the adaptation of the spectrophotometer in order to permit measurements of temperature-dependent absorbance [7]. The sample was initially immersed in a temperature-controlled water-bath for thermal pre-equilibration. Thereafter, a sample aliquot was selected and placed inside a specially designed temperature-controlled cell where absorbance was measured. In the more sophisticated versions, the instrument was furnished with a peristaltic pump for propelling the sample solution towards the cell and then to waste. 

There were situations where the analyte needed to be converted into a more detectable species, and thus reagent addition was often required. These steps were efficiently accomplished in a flow system, as demonstrated in the determination of chlorine in waters [8]. A potassium iodide solution merged with the sample flowing stream, and the mixture passed through a coil, so that enough time for the stoichiometric release of iodine was achieved, and the liberated species was electrochemically determined. 

The steam reforming reaction was introduced to industry more than 75 years ago, although the reaction had not been subject to many scientific studies [381] [389], Early work in the 19th century included reactions of hydrocarbons and steam over calcium oxide [487] and a cyclic process using nickel [543], 

The reforming process was adopted mainly in the US where natural gas was easily available as feedstock, whereas reformers in Europe were initially reduced to operate on propane and LPG. 

The first patent on a tubular reformer using supported nickel catalysts was obtained by BASF in 1912 [348] [544]. A later patent (1928) dealt with a heated tubular reactor [546]. A license was given to Standard Oil, New Jersey, and the first industrial reformer was started in Baton Rouge in 1930 [93]. Six years later, the first ICI reformer was commissioned at Billingham [203], 

The introduction of high-pressure reforming meant that the energy consumption of the ammonia S5mthesis could be decreased significantly (refer to Section 2.5) As a result, a munber of natural gas-based ammonia plants were built in the US, primarily by M.W. Kellogg in the mid-1960s [224] [312], 

The steam reforming process became the preferred technology for synthesis gas for methanol and other petrochemicals, oxo-alcohols, acetic acid, etc. [88], [425]. 

The interaction of poly(ethylene oxide) and other polar polymers with metal salts has been known for many years (Bailey and Koleska, 1976). Fenton, Parker and Wright (1973) reported that alkali metal salts form crystalline complexes with poly(ethylene oxide) and a few years later, Wright (1975) reported that these materials exhibit significant ionic conductivity. Armand, Chabagno and Duclot (1978, 1979) recognised the potential of these materials in electro-chemical devices and this prompted them to perform more detailed electrical characterisation. These reports kindled research on the fundamentals of ion transport in polymers and detailed studies of the applications of polymer-salt complexes in a wide variety of devices. 

Poly(ethylene oxide) (usually abbreviated to PEO) has been the most intensively studied host polymer for polymer electrolytes and it serves as a prototype for the structural features in most of the more advanced polymer electrolyte hosts. It consists of —O—CHj—CHj— repeat units and occurs as a semicrystalline solid. The relative orientations of groups 

The single screw as an extrusion apparatus was developed in the second half of the 19th century and was used intensively in industrial and heavy engineering applications. It was used in three major industries  

2 Historical Development of the Co-Rotating Twin Screw [References on page 33 ) 

The adhesion and friction characteristics of the plastic material determine the intensity of the flow. In the case of Newtonian fluids this is half of the theoretical conveying (at constant pressure) and even less with counterpressure (extrusion), even down to zero. In the latter case, the product rotates with the shaft and throughput ceases. 

Naturally this team, part of the chemical industry, was primarily involved with solving problems in the area of high-viscosity engineering, particularly in developing chemical processes for the Bayer AG. The mechanical aspect was developed as required and to varying degrees of intensity. 

With respect to screw geometry, we turn back the clock to Wolfen, where the team was searching for the perfect mechanical apparatus for high-viscosity technology. It had to function despite the adhesive, frictional, and antifrictional properties of the product, cope with various material consistencies, and overcome rheological changes caused, for instance, by reactions in the machine. 

2-fluorobutadiene-l,3, the monomer for Fluoroprene, was prepared by the gas phase addition of anhydrous hydrogen fluoride to monovinyl acetylene  

This route is analogous to the acetylene route to chloroprene as also were the polymerization methods employed. The properties of the resulting elastomer, Fluoroprene, were far from outstanding and production was soon discontinued. 

Attempts to improve thermal and chemical stability were made by polymerizing other, generally more highly fluorinated, butadienes. Several copolymers were also prepared using at least one of these monomers. Typical members of this group of monomers are  

In overall properties these materials did not show any significant advantages over either polychloroprenes or nitrile rubbers. An interesting review of these polymers has been published (Cooper, 1968). 

Although no longer of commercial significance the poiyfluoroacrylates have been used as elastomers. The monomers were prepared from carboxylic acids by the following reaction sequence  

The first organic tandem solar cell was published in 1990 by Hiramoto et al, who employed two identical subcells composed of bilayers of a metal-free phthalocyanine and a perylene tetracarboxylic derivative with an ultrathin Au layer to interconnect the two subcells to achieve an almost doubling of the voltage. More than a decade later, in 2002, Forrest et reported on two, three, and five stacked heterojunction cells consisting of copper phthalocyanine (CuPc) as a donor and perylenetetracarboxylic bis-benzimidazole (PCTBI) as an acceptor. Ultrathin ( 5 A) layers of Ag clusters were placed between the heterojunctions to interconnect the subcells. Similar results were described by Tsutsui et In 2004, Leo and Pfeifer et intro- 

The next step was the use of solution processed charge transport layers in the recombination contact of polymer solar cells. In 2007, Gilot et al. showed that ZnO nanoparticles processed from acetone can be covered with a layer of pH-neutral PEDOTrPSS spincoated from a dispersion in water to fabricate a ZnO/PEDOT PSS recombination layer that is transparent to light and makes an almost loss-less recombination layer for tandem and triple junction cells. This approach bears similarity to the p- and n-doped wide bandgap transport layers developed for evaporated small molecule tandem cells. The ZnO/PEDOT PSS recombination contact was initially employed in 

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If no appraisal was performed, and the development was started based, say, on the medium case STOMP of 48 MMstb, then the actual STOMP would not be found until the facilities were built and the early development wells were drilled. If it turned out that the STOMP was only 20 MMstb, then the project would lose 40 million, because the facilities were oversized. If the STOMP is actually 48 MMstb, then the NPV is assumed to be the same as for the medium case after appraisal. If the STOMP was actually 100 MMstb, then the NPV of + 40 million is lower than for the case after appraisal (+ 66 million) since the facilities are too small to handle the extra production potential. 

Ferguson E E 1992 A personal history of the early development of the flowing afterglow technique for ion molecule reactions studies J. Am. Soc. Mass Spectrom. 3 479-86... 

Another approach to mass analysis is based on stable ion trajectories in quadnipole fields. The two most prominent members of this family of mass spectrometers are the quadnipole mass filter and the quadnipole ion trap. Quadnipole mass filters are one of the most connnon mass spectrometers, being extensively used as detectors in analytical instnunents, especially gas clnomatographs. The quadnipole ion trap (which also goes by the name quadnipole ion store, QUISTOR , Paul trap, or just ion trap) is fairly new to the physical chemistry laboratory. Its early development was due to its use as an inexpensive alternative to tandem magnetic sector and quadnipole filter instnunents for analytical analysis. It has, however, staned to be used more in die chemical physics and physical chemistry domains, and so it will be described in some detail in this section. 

Comisarow M B and Marshall A G 1996 Early development of Fourier transform ion cyclotron resonance (FT-ICR) spectroscopy J. Mass Spectrom. 31 581-5... 

One writes equations which T and T" are expected to obey. For example, in the early development of these methods [80], the Scln-ddinger equation itself was assumed to be obeyed, so = E V and = E are the two equations (note that, in the IP and EA cases, the latter equation, and the associated Hamiltonian //, refer to one fewer and one more electrons than does the reference equation ft V = E V). 

Frontier orbital analysis is a powerful theory that aids our understanding of a great number of organic reactions Its early development is attributed to Professor Kenichi Fukui of Kyoto University Japan The application of frontier orbital methods to Diels-Alder reactions represents one part of what organic chemists refer to as the Woodward-Hoffmann rules a beautifully simple analysis of organic reactions by Professor R B Woodward of Harvard University and Professor Roald Hoffmann of Cornell University Professors Fukui and Hoffmann were corecipients of the 1981 Nobel Prize m chemistry for their work... 

In principle, emission spectroscopy can be applied to both atoms and molecules. Molecular infrared emission, or blackbody radiation played an important role in the early development of quantum mechanics and has been used for the analysis of hot gases generated by flames and rocket exhausts. Although the availability of FT-IR instrumentation extended the application of IR emission spectroscopy to a wider array of samples, its applications remain limited. For this reason IR emission is not considered further in this text. Molecular UV/Vis emission spectroscopy is of little importance since the thermal energies needed for excitation generally result in the sample s decomposition. 

Formaldehyde, HCHO, is a primary and necessary constituent of the first five synthetic adhesives in the listing. It is a simple organic chemical first identified during the latter half of the 1800s. Its irritating and toxic odor and preservative properties were known from the time of its early development. It is a ubiquitous chemical, formed naturally in small quantities by every process of incomplete combustion as well as in normal biologic processes. The human body has a natural formaldehyde level of about 3 lg/g, ie, 3 parts per million (ppm) in the blood at all times. 

The early developments of solvent processing were concerned with the lubricating oil end of the cmde. Solvent extraction processes are appHed to many usefiil separations in the purification of gasoline, kerosene, diesel fuel, and other oils. In addition, solvent extraction can replace fractionation in many separation processes in the refinery. For example, propane deasphalting (Fig. 7) has replaced, to some extent, vacuum distillation as a means of removing asphalt from reduced cmde oils. 

Ref. 6 is a classic exposition of the early development of dmg—receptor iateractions. 

Composites. The history of phenoHc resin composites goes back to the early development of phenoHc materials, when wood flour, minerals, and colorants were combined with phenoHc resins to produce mol ding compounds. In later appHcations, resin varnishes were developed for kraft paper and textile fabrics to make decorative and industrial laminates. Although phenoHcs have been well characterized in glass-reinforced composites, new developments continue in this area, such as new systems for Hquid-injection molding (LIM) and sheet-molding compounds (SMC). More compHcated composite systems are based on aramid and graphite fibers. 

The earliest significant technical work on piezoelecttic ink jet began in the 1930s and the first tme commercial activity was begun in the late 1960s. This early development effort, aimed at office printing appHcations, had limited commercial success. The first successful piezoelecttic ink-jet printer was introduced in 1977. It printed a relatively cmde character set using an array of 12 jets in its printhead. 

Germany, the United Kingdom, and the United States shared ahke in the early development of stainless steels. In the United Kingdom in 1912, during the search for steel that would resist fouling in gun barrels, a corrosion-resistant composition containing 12.8% chromium and 0.24% carbon was reported. It was suggested that this composition be used for cutiery. In fact, the composition of AISI Type 420 steel (12—14% chromium, 0.15% carbon) is similar to that of the first corrosion-resistant steel. 

The first successful appHcation of heterogeneous azeotropic distillation was in 1902 (87) and involved using benzene to produce absolute alcohol from a binary mixture of ethanol and water. This batch process was patented in 1903 (88) and later converted to a continuous process (89). Good reviews of the early development and widespread appHcation of continuous azeotropic distillation in the prewar chemical industry are available (90). 

The early development of the nylons is largely due to the work of W. H. Carothers and his colleagues, who first synthesised nylon 66 in 1935 after extensive and classical researches into condensation polymerisation. Commercial production of this polymer for subsequent conversion into fibres was commenced by the Du Pont Company in December 1939. The first nylon mouldings were produced in 1941 but the polymer did not become well known in this form until about 1950. 

The phenolic resins may be considered to be the first polymeric products produced commercially from simple compounds of low molecular weight, i.e they were the first truly synthetic resins to be exploited. Their early development has been dealt with briefly in Chapter 1 and more fully elsewhere. ... 

Laminates prepared from highly chlorinated resins of this type tend to discolour on prolonged exposure to light and this retarded the early development of these resins. Stabilisers have, however, been developed and current resins are substantially superior to the early resins of this type. 

Ruska, E. (1980) The Early Development of Electron Lenses and Electron Microscopy (Hirzel, Stuttgart). 

In the early development of such limits, they were generally known as Maximum Allowable Concentrations or MACs, sometimes called Maximum Acceptable Concentrations, or Maximum Permissible Concentrations. 

Here lies the crux of the major problem in the early development of the gas turbine. The compressor must be highly efficient-it must use the minimum power to compress the gas the turbine must also be highly efficient-it must deliver the maximum power if it is to drive the compressor and have power over. With low compressor and turbine efficiency, the plant can only just be self-sustaining-the turbine can drive the compressor but do no more than that. 

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